1. Field of the Invention:
The present invention relates generally to single flow valves, and more particularly to a single-flow valve for use in a hypodermic needle.
2. Description of the Prior Art:
The re-use of needles by intravenous drug abusers, a group that numbers approximately 750,000 nationally, results in various infections, including hepatitis, and AIDS (Acquired Imuno deficiency Syndrome).
Hepatitis is believed to be widespread among the drug addict population, whose dirty needles spread the disease from one addict to another. While hepatitis has heretofore been considered to be a suburban problem, such has proven otherwise as large numbers of cases of hepatitis have been in found in urban and rural areas.
In regard to the AIDS disease, while it was initially confined mostly to certain sub-sets of the general population, namely homosexuals and drug addicts, the AIDS virus is now beginning to spread into the general population. The main force behind this spread of AIDS appears to be the intravenous drug abusers. As the Commissioner of the New York State Department of Health, Stephen C. Joseph, M.D., M.Ph. reports, "The spread of the AIDS virus will not be slowed, nor will its seepage into the heterosexual community be prevented, without a meaningful war on drugs. The future of the epidemic lies with the connection between AIDS and the intravenous drug abuser."
The degree to which the AIDS epidemic has spread is uncertain. Estimates vary widely, but there is agreement that the AIDS epidemic is spreading and that the costs to society, in terms of dollars spent and productivity lost, will continue to rise exponentially into the coming decade. Various estimates of these costs that have appeared in journals and periodicals include: $1 billion in the U.S. in 1987; Annual U.S. AIDS costs of $66.4 billion by 1991; New York cost of $2 billion in 1991; 100 million individuals exposed by 1990; seven-fold increase in cases from heterosexual transmission by 1990; and 120,000 to 270,000 cumulative cases in the U.S. by 1991. A British District's study projects AIDS to surpass heart disease as the leading cause of life years lost by 1990.
The attack on AIDS has been multi-directional, namely testing, treatment, vaccine, education and prevention.
In regard to testing, testing methods have been developed and are in place, but questions remain as to their absolute effectiveness. New strains of the virus, and the time lag between infection and antibody formation have raised concern that present testing methods are inadequate.
In regard to treatment, treatment regimens are being developed very aggressively, but hopes are a "cure" soon are small. Controlling symptoms and reducing infectivity are more likely outcomes.
In regard to vaccine production, which is the traditional method of choice to combat viral diseases, progress has been slow. Journal of the American Medical Association recently reported, in essence, that it was predicted a year ago that it would take a minimum of five years to develop a vaccine against HIV (AIDS virus), and that things today are even bleaker.
In regard to education, it is in the process of being expanded, particularly centering around the disease itself and preventing its spread. Although many myths and misconceptions still exist, increasingly the facts are being disseminated. The effectiveness of education towards changing behavior is also a concern.
In regard to the prevention of AIDS, for the general public and homosexual sub-population, prevention involves the practice of "safe sex". Prevention for the intravenous drug abuser means the use of sterile needles. Although new needles are packaged sterily, and intended for single use, intravenous drug users routinely re-use needles. While the "safe" practice of one user always using the same needle is fine in theory, this happens only infrequently at best.
Our understanding of the behavior patterns governing intravenous drug abusers' needle sharing is inadequate. There are inherent problems in data collection involving this illegal activity. It is known that needle sharing has been previously associated with the communal ritual of drug use, and that intravenous drug users, when experiencing withdrawal, will use whatever means is at hand to administer the drugs.
As a result of the serious problem presented by the AIDS epidemic, there has been an increased demand for clean needles with several resultant market responses. In the New York City area, sellers of the drugs are including two new needles with every purchase, instead of the standard one, and there has been an emergence of the repackaging of needles and selling them as new. Long term results of this practice are unpredictable, but potentially catastrophic. Accordingly, preventing re-use of needles would help contain the spread of AIDS, as well as reduce the incidence of any other infectious diseases, such as hepatitis, which are spread through intravenous drug abuse.
The application of this invention to hypodermic needles would change needles that are currently intended for single use, into those that in fact can only be used a single time. In theory, if such needles were exclusively used, the exposure of new individuals to AIDS, and other diseases, via blood routes, would be virtually eliminated, and an entire avenue of transmission would be eliminated. While this change in needle design would not eliminate the use of currently existing dirty needles, through needle exchange programs, clean non-reuseable needles would systematically replace unsterile needles currently in use at a rate restricted only by the success of such programs, and the continued availability of needles susceptible to abuse.
In regard to the patented art, a single-use syringe is disclosed in U.S. Pat. No. 3,951,146, which issued to Chiquiar-Arias on April 20, 1976. This patent is directed to a blade-containing syringe, which self-destructs upon a pressing of the plunger thereof during the expelling of the syringe contents. Also, U.S. Pat. No. 4,233,975, which issued to Yerman on Nov. 18, 1980, is directed to an anti-drug abuse single-use syringe having a plug member adapted to be pushed into a position blocking flow to and from the needle passage as the plunger's proximal portion is moved inwardly to expel the syringe contents. In the blocking position, the plug member is locked into a female member positioned to permit movement of the plug member to the blocking position, but preventing withdrawal of the plug member from the blocking position, thereby preventing subsequent intake or outflow through the syringe needle passage. The use of valve means is further disclosed in U.S. Pat. No. 3,557,778, which issued to Hughes on Jan. 26, 1971. The Hughes patent is directed to a blood specimen collection assembly, having a fluid inlet and a fluid outlet with valve means disposed within the assembly for movement to and from an open and closed positions. The valve means prevents the backflow of testing fluid from the specimen receptacle into the patient's bloodstream during use of the blood specimen collection assembly.